The HUB is the beating heart of your factory in Satisfactory. It is where you will work on your Milestones, and build important upgrades that will allow you to do new things in the game. The HUB is the first building you will be able to build, and you will need to start upgrading it almost immediately.
To upgrade the HUB, interact with the small console on it, then select the HUB Tier you wish to upgrade to. The screen will show you the benefits and new equipment you get from the upgrade. On the “Select Milestone” tab, click on Tier 0, then Hub Upgrade 1.
This upgrade requires 10 Irons Rods to complete. To get Iron Rods, you will first need Iron Ore. Head to the Iron Ore deposit that you previously discovered and mine some Iron from it. Now, go to the Crafting Bench on the HUB and turn Iron Ore into Iron Ingots, and then the Iron Ingots into Iron Rods.
To craft an item, just click on it in the list shown on the left below, then hold the crafting button as it cycles through producing one item at a time.
Go back to the HUB console, and move the Iron Rods from your inventory over to the small resource slot shown in the image above. You will then be able to upgrade the HUB to the next level.
Each HUB upgrade will need more resources, of different types, and you will normally need to build the items that you get from each upgrade to move on to the next Tier. Also, you can break down the move the HUB without losing access to your upgrades, which is an important feature to keep in mind if you end up placing the HUB poorly, or need to relocate it to a more resource-rich area later in the game.